public String intercept()

in plugins/json/src/main/java/org/apache/struts2/json/JSONInterceptor.java [75:186]
83 lines of code
17 McCabe index (conditional complexity)

    public String intercept(ActionInvocation invocation) throws Exception {
        HttpServletRequest request = ServletActionContext.getRequest();
        HttpServletResponse response = ServletActionContext.getResponse();

        String requestContentType = readContentType(request);
        String requestContentTypeEncoding = readContentTypeEncoding(request);

        Object rootObject = null;
        final ValueStack stack = invocation.getStack();
        if (this.root != null) {
            rootObject = stack.findValue(this.root);

            if (rootObject == null) {
                throw new RuntimeException("Invalid root expression: '" + this.root + "'.");
            }
        }

        if (jsonContentType.equalsIgnoreCase(requestContentType)) {
            // load JSON object
            Object obj = JSONUtil.deserialize(request.getReader());

            // JSON array (this.root cannot be null in this case)
            if(obj instanceof List && this.root != null) {
                String mapKey = this.root;
                rootObject = null;

                if(this.root.indexOf('.') != -1) {
                    mapKey = this.root.substring(this.root.lastIndexOf('.') + 1);

                    rootObject = stack.findValue(this.root.substring(0, this.root.lastIndexOf('.')));
                    if (rootObject == null) {
                        throw new RuntimeException("JSON array: Invalid root expression: '" + this.root + "'.");
                    }
                }

                // create a map with a list inside
                Map m = new HashMap();
                m.put(mapKey, new ArrayList((List) obj));
                obj = m;
            }

            if (obj instanceof Map) {
                Map json = (Map) obj;

                // clean up the values
                if (dataCleaner != null)
                    dataCleaner.clean("", json);

                if (rootObject == null) // model overrides action
                    rootObject = invocation.getStack().peek();

                // populate fields
                populator.populateObject(rootObject, json);
            } else {
                LOG.error("Unable to deserialize JSON object from request");
                throw new JSONException("Unable to deserialize JSON object from request");
            }
        } else if (jsonRpcContentType.equalsIgnoreCase(requestContentType)) {
            Object result;
            if (this.enableSMD) {
                // load JSON object
                Object obj = JSONUtil.deserialize(request.getReader());

                if (obj instanceof Map) {
                    Map smd = (Map) obj;

                    if (rootObject == null) { // model makes no sense when using RPC
                        rootObject = invocation.getAction();
                    }

                    // invoke method
                    try {
                        result = this.invoke(rootObject, smd);
                    } catch (Exception e) {
                        RPCResponse rpcResponse = new RPCResponse();
                        rpcResponse.setId(smd.get("id").toString());
                        rpcResponse.setError(new RPCError(e, RPCErrorCode.EXCEPTION, getDebug()));

                        result = rpcResponse;
                    }
                } else {
                    String message = "SMD request was not in the right format. See http://json-rpc.org";

                    RPCResponse rpcResponse = new RPCResponse();
                    rpcResponse.setError(new RPCError(message, RPCErrorCode.INVALID_PROCEDURE_CALL));
                    result = rpcResponse;
                }
            } else {
                String message = "Request with content type of 'application/json-rpc' was received but SMD is "
                        + "not enabled for this interceptor. Set 'enableSMD' to true to enable it";

                RPCResponse rpcResponse = new RPCResponse();
                rpcResponse.setError(new RPCError(message, RPCErrorCode.SMD_DISABLED));
                result = rpcResponse;
            }

            JSONUtil jsonUtil = invocation.getInvocationContext().getContainer().getInstance(JSONUtil.class);

            String json = jsonUtil.serialize(result, excludeProperties, getIncludeProperties(),
                    ignoreHierarchy, excludeNullProperties);
            json = addCallbackIfApplicable(request, json);
            boolean writeGzip = enableGZIP && JSONUtil.isGzipInRequest(request);
            JSONUtil.writeJSONToResponse(new SerializationParams(response, requestContentTypeEncoding,
                    this.wrapWithComments, json, true, writeGzip, noCache, -1, -1, prefix, "application/json"));

            return Action.NONE;
        } else {
            LOG.debug("Accept header parameter must be '{}' or '{}'. Ignoring request with Content Type '{}'", jsonContentType, jsonRpcContentType, requestContentType);
        }

        return invocation.invoke();
    }